It makes more sense than Asuka/Touji, and they hooked up in the alternate live action. Consider base compatibility. Asuka is a bitch, Kaworu is a douche. Kaworu is the only one who would put up with her shit.
True, but the anime is just one part of the franchise. They have more interaction in the various manga series, NGE, GOS2, ISIK, Datenroku, and even Petit Eva. Not to mention various video games, fan fiction, etc.